The invention relates to a switching device which can be variably positioned, in particular a press brake, which is connected, preferably wirelessly, to a control device which may cooperate with a production unit, in particular a press brake, for transmitting signals and/or data, and a production unit, in particular a press brake, for shaping workpieces of sheet metal, with at least one control device which is connected, preferably wirelessly, to a switching device, which can be variably positioned as necessary, for transmitting signals and/or data.
Switching devices are used in a broad range of applications for controlling and regulating different sequences, parameters, etc. The switching devices specifically used with production units as a means of controlling work steps, production sequences, etc., are commonly provided in the form of foot switches to permit easy operation or manipulation by an operator. If the operator using the production unit has to go off to another location, the operator must manually re-position the switching device so that he can continue to control the switching device and thus enable other work steps or sequences of the production unit to be initiated by operating the switching device. Such switching devices are used on press brakes, for example, and in this instance a workpiece of sheet metal is preferably formed between two bending tools when the switching device is operated, but it may be that the operator has to move to another area because the sheet metal workpiece often has to be exactly positioned in the press brake from more than one side to ensure accurate production. This manual re-positioning of the switching device is very time-consuming and does not lend itself to a rapid work sequence at the production unit, thereby significantly increasing the cost of the production process at the production unit.
Various possible switching devices have been described in the prior art which permit a change in operating position.
Such a switching device is described in patent specification DE 691 15 553 D2. The described switching device, which can be depressed from any point, is provided in the form of a switch mat, which has a detector for detecting a change in pressure at any point within an operating zone, and the switching device has flexible top and bottom layers which enable the switching device to be adapted to the ground underneath within certain limits and which are of a moisture-resistant and anti-slip design. The switch mat also contains a power source and a generator for electromagnetic waves, which is actively connected to the detector so that an electromagnetic wave is sent to a point remote from the switching device in response to a detected change in pressure at any point within the operating zone.
The disadvantage of such a switching device is that if a large operating zone is required, the switch mat must have a wide extension along a standing surface, which means that extra space is needed which can not be used for other purposes except under certain conditions because of the size of the switch mat. Apart from this aspect, the costs of using such a switch mat are also significantly increased due to the higher production costs incurred as a result of using a switch mat of large dimensions. One disadvantage is the fact that the switching device takes up a large area of a standing surface in order to provide a wide operating zone on the one hand, but the space occupied by the switch mat must be limited to an area which is not in the immediate working range of an operator in order to prevent inadvertent operation on the other hand. This being the case, it is not possible to use the switch mat in an area of standing surface which the operator has to walk on, which means that the operator constantly has to orient himself depending on the position of the switch mat in order to operate it correctly.
Patent specification AT 333160 also discloses a physically operated work contact which is carried on the body of a person and has a miniature transmitter which is actively connected to a remote receiver. The physically operated work contact is disposed in a shoe, on the sole in the region of the toes, and has two contact elements and a transmitter, which emits control signals when the contact elements are closed.
The disadvantage of this approach is that there is a possibility of unintentionally operating the alarm signal transmitter, which would mean that it would only be possible to use a production unit, such as a press brake for example, under certain conditions and possibly not at all because the requisite safety conditions of the switching device to prevent inadvertent operation are not fulfilled. Another disadvantage is the fact that in order to be able to operate the alarm signal transmitter from any location, it has to be disposed in a special shoe or a special sole, and it is also preferable to provide a transmitter in the shoe sole, and an operator must therefore be equipped with special shoes, which also incurs extra costs. The switching device is also limited to a very small and lightweight design to avoid hampering the operator, which makes it impossible to equip the switching device with a broad range of functions.
The objective of the invention is to propose a switching device and a production unit designed to permit easy positioning of the switching device.
This objective is achieved by the invention due to the characterizing features defined in claim 1. The surprising advantage of this approach is that the position of the switching device can be varied and a change in position takes place automatically whenever a change in the position of an element to be detected is perceived. This saves time when it comes to operating the switching device because the operator controlling the switching device does not have to move depending on the position of the switching device and instead, the switching device is automatically positioned so that easy operation is possible, thereby cutting costs, and changes in position can be perceived in an area to be detected and then evaluated by the control unit, after which control signals can be transmitted to a drive system to enable accurate positioning of the switching device.
Also of advantage are embodiments defined in claims 2 and 3 because monitoring of an area or section can be guaranteed and any changes in the position of elements to be detected can be easily detected.
Another advantageous embodiment is described in claims 4 to 8, the resultant advantage being that equipment which provides accurate measurements and has been tried and tested can be used for monitoring purposes.
The embodiments defined in claims 9 and 10 also offer advantages because the switching device or production unit may be designed to fulfill the detection function if necessary, or the detection accuracy can be improved if necessary by using different detection methods.
The advantage of an embodiment defined in claims 11 to 15 is that the change in position or positioning operation of the switching device can be controlled and regulated, thereby enabling exact positioning.
Other advantageous embodiments are defined in claims 16 to 19, whereby the position of the switching device can be changed independently of the production unit and the direction of the switching device can be easily changed.
An embodiment defined in claim 20 is of advantage because devices which specifically require electrical power for operation can be used in the switching device.
An embodiment defined in claim 21 is of advantage because it permits easy operation of the switching device.
The advantage of the embodiments defined in claims 22 and 23 is that the switching device can be operated wirelessly, thereby avoiding cables and wiring which could otherwise compromise operating safety.
An embodiment defined in claim 24 offers a simple way of operating the switching device.
Also of advantage is an embodiment defined in claim 25, because easy movement of the switching device can be guaranteed and all the desired devices can be reliably accommodated on the switching device.
The embodiments defined in claims 26 and 27 are also of advantage because different operating modes, settings, etc., can be defined in a simple manner and rendered visible.
The advantages gained correspond to at least some of those described above in connection with the embodiments specified in claims 1 to 27 or will become apparent from the description given below.